Algal Growth

Growth and decay of algae/chlorophyll $a$ is calculated as a function of the growth rate, the respiration rate, the settling rate and the amount of algae present in the stream. The change in algal biomass for a given day is:

$\Delta algae=((\mu _a*algae)-(\rho_a*algae)-(\frac{\sigma_1}{depth}*algae))*TT$ 7:3.1.2

where $\Delta algae$ is the change in algal biomass concentration (mg alg/L), $\mu_a$ is the local specific growth rate of algae (day$^{-1}$ or hr$^{-1}$), $\rho_a$ is the local respiration or death rate of algae (day$^{-1}$ or hr$^{-1}$), $\sigma_1$ is the local settling rate for algae (m/day or m/hr), $depth$ is the depth of water in the channel (m), $algae$ is the algal biomass concentration at the beginning of the day (mg alg/L), and $TT$ is the flow travel time in the reach segment (day or hr). The calculation of depth and travel time are reviewed in Chapter 7:1.